The overall objectives of the total project are (a) to determine how small molecules and their metabolic products affect the stability and function of hemoglobin and other blood proteins and (b) to develop basic biochemical methods that are applicable to the objectives. Small molecules relevant to this project include drugs, industrial chemicals, and environmental pollutants that cause hemolytic anemia and methemoglobinemia. Research goals for the coming year are (1) to identify the products of the reaction of phenylhydrazine with hemin or octaethylhemin in the presence of oxygen, (2) to identify the oxidation products of hemin when phenylhydrazine reacts with oxyhemoglobin and oxymyoglobin; (3)) to determine the effect of substitutions of the benzene ring of phenylhydrazine on the rates of reaction of substituted phenylhydrazines with oxyhemoglobin; (4) to determine the chemical nature of the initial product in the reaction of pheylhydrazine with oxyhemoglobin, and (5) to complete studies on the binding site of radioactivity from 14C-phenylhydrazine on the globin portion of hemoglobin.